1. Field of the Invention
The present invention relates to an ink jet recording ink used in ink jet recording type recording devices such as printers, copiers, facsimile machines, word processors, and plotters. The present invention also relates to an ink jet recording method using the ink and to a method for producing the ink.
2. Description of the Related art
Inks used in ink jet recording devices primarily comprises a solvent, colorants, and additives. It is required for the ink jet ink to possess the following characteristics.
(1) Inks may produce a uniform image having high resolution and high density and being free from any blur nor fogs on paper. PA0 (2) Inks may brings about no clogging at the tip of a nozzle caused by dried ink and always has high jetting responsibility and stability. PA0 (3) Inks may provide excellent drying characteristics on paper. PA0 (4) Inks may provide an image having good fastness. PA0 (5) Inks may provide have high long-term storage stability.
Various trials have been made to satisfy the above demands. The aforementioned drying characteristics (3) of the ink is important to raise the operational speed of a recording device and prevent color-mixing blur in a color printing operation. For this reason, some improvements have been made in which a solvent having high penetrability and volatility is used and a surfactant is added. In respect of the fastness (4) of an image, there are many disclosures relating to ink using a pigment as the colorant instead of a dye to improve the resistance to water. However, for example, the pigment-containing ink has the drawback that the rubbing resistance is inferior to that of the dye ink although it is improved in the resistance to water. With regard to the long-term storage stability (5), the ink using a pigment usually tends to be inferior in the stability to the ink using a dye. To improve the aforementioned drawbacks in the case of using a pigment, there have been disclosed various methods including a method of introducing a substituted group containing a water solubilizing group into carbon black as disclosed in U.S. Pat. No. 5,571,311, a method of polymerizing an aqueous monomer or the like on the surface of carbon black as disclosed in Japanese Patent Application Laid-Open (JP-A) No. 8-81646, and a method of oxidizing carbon black as disclosed in JP-A Nos. 8-3498 and 8-319444.
Also disclosed are, for example, a method in which no dispersant is used, but an aqueous dispersion containing carbon black stabilized by grafting is used instead (Japanese Patent Application Publication (JP-B) No. 1-49369), a method using ink comprising the carbon black produced by reacting a carbon black with a reactive polymer (JP-A Nos. 1-79278 and 6-128517) and a method using ink in which the carbon black is surface-treated by graft-polymerizing an acrylamide derivative (JP-A No. 5-230410).
As aforementioned, various improving methods have been proposed. However, no method reaches the level sufficiently satisfying the characteristics required for the ink jet, ink. Thus the object characteristics are not attained.